startActivity() 方法returns 出错。 / 片段 - Android

Question

我有两个 class 被片段覆盖。

startActivity()方法returns出错。

当我的 home.java class 中名为 btn 的按钮被点击时。我想在名为 class 的 hometwo.java 中单击名为 btnctwo 的按钮。

但是我得到一个错误。

logcat

 .sahnartsappone.sahnartsapp.hometwo}; have you declared this activity in your AndroidManifest.xml?

我是否需要像下面的示例代码一样将 hometwo.java class 添加到我的 AndroidManifest 文件中？

<activity  
         android:name=".hometwo"  
         android:screenOrientation="portrait" />

我将 hometwo.java class 添加到我的 AndroidManifest 文件中，就像我上面提到的代码示例一样。但是我得到一个错误。

为什么我需要将 hometwo.java class 添加到我的 AndroidManifest 文件中？

home.java

public class home extends Fragment {
    Button btn;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.home, container, false);
        tn =  rootView.findViewById(R.id.btnc);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getActivity(), hometwo.class);
                intent.putExtra("Indicator", true);
                startActivity(intent);
            }
        });

        return rootView;
    }
}

hometwo.java

public class hometwo extends Fragment {
    Button btnctwo;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.home, container, false);
        btnctwo =  rootView.findViewById(R.id.btnctwo);

        Bundle b = getActivity().getIntent().getExtras();
        if (b != null) {
            if (b.containsKey("Indicator"))
                btnctwo.performClick();
        }

        btnctwo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.e("testler","testlertwo");
            }
       });
       return rootView;  
    }
}

logcat

2020-05-17 16:21:10.944 9826-9826/com.sahnartsappone.sahnartsapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.sahnartsappone.sahnartsapp, PID: 9826
    android.content.ActivityNotFoundException: Unable to find explicit activity class {com.sahnartsappone.sahnartsapp/com.sahnartsappone.sahnartsapp.hometwo}; have you declared this activity in your AndroidManifest.xml?
        at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:2049)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1709)
        at android.app.Activity.startActivityForResult(Activity.java:5192)
        at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:676)
        at androidx.core.app.ActivityCompat.startActivityForResult(ActivityCompat.java:234)
        at androidx.fragment.app.FragmentActivity.startActivityFromFragment(FragmentActivity.java:791)
        at androidx.fragment.app.FragmentActivity$HostCallbacks.onStartActivityFromFragment(FragmentActivity.java:933)
        at androidx.fragment.app.Fragment.startActivity(Fragment.java:1185)
        at androidx.fragment.app.Fragment.startActivity(Fragment.java:1173)
        at com.sahnartsappone.sahnartsapp.home.onClick(home.java:29)
        at android.view.View.performClick(View.java:7125)
        at android.view.View.performClickInternal(View.java:7102)
        at android.view.View.access00(View.java:801)
        at android.view.View$PerformClick.run(View.java:27336)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

Answer 1

这个问题没有答案。

that's not how you start a fragment. you're trying to start a fragment as an activity, which it isn't @a_local_nobody

startActicity () 方法在由片段扩展的 class 中不起作用。

 Intent intent = new Intent(getActivity(), hometwo.class);
        intent.putExtra("Indicator", true);
        startActivity(intent);

感谢@a_local_nobody

startActivity() 方法returns 出错。 / 片段 - Android

The startActivity () method returns an error. / Fragment - Android

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